Photosensitive input device and photosensitive input panel

ABSTRACT

A photosensitive input device includes a stylus, a photosensitive input panel including an induction layer, a photoelectric detecting circuit, a driving circuit, a controller, and a storage device. The induction layer includes a plurality of photosensitive units including a light-emitting element and a light-receiving element together. The photosensitive element outputs a current when struck by the light from the stylus, the current intensity being dependent on the wavelength of the emitted light. The photoelectric detecting circuit determines coordinates based on the induced current and the intensity of the induced current. The driving circuit generates a driving current or a reduced or a zero current in response, based on a pre-determined table and outputs the driving current to show the track of the stylus-light across the input panel, by illuminating the relevant light-emitting elements or by switching down or switching off the relevant light-emitting elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

Related subject matter is disclosed in co-pending U.S. patentsapplication with an Attorney Docket Number US48712 and a title ofPHOTOSENSITIVE INPUT-OUTPUT DEVICE AND PHOTOSENSITIVE INPUT-OUTPUTPANEL, which has the same assignees as the current application and wasconcurrently filed.

BACKGROUND

1. Technical Field

The present disclosure relates to input devices and particularly to aphotosensitive input device and a photosensitive input panel.

2. Description of the Related Art

LED display devices with touch screens are common, and such touchscreens generally include a touch panel positioned over a LED displayscreen or a plurality of touch detecting elements integrated with theLED display screen, thus resulting in increased thickness of the LEDdisplay device as well as heat generation, and further decreasing thebrightness of the display screen in the touch screens.

Therefore, there is room for improvement within the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The components in the drawings are not necessarily drawn to scale, theemphasis instead being placed upon clearly illustrating the principlesof the disclosure. Moreover, in the drawings, like reference numeralsdesignate corresponding parts throughout the several views.

FIG. 1 is a schematic view of a photosensitive input device according toan exemplary embodiment.

FIG. 2 is a schematic view of an induction layer of the photosensitiveinput device of FIG. 1.

FIG. 3 is a block diagram of the photosensitive input device of FIG. 1.

DETAILED DESCRIPTION

Referring to FIG. 1, a photosensitive input device 1 according to anexemplary embodiment includes a photosensitive input panel 2 and astylus 3. The photosensitive input panel 2 includes a substrate 20, aninduction layer 21, and a cover 22. The induction layer 21 is sandwichedbetween the substrate 20 and the cover 22. The stylus 3 emits lightswith specific wavelengths.

Referring to FIG. 2, the induction layer 21 includes m*n photosensitiveunits 210, where m, n are natural numbers. Each of the photosensitiveunits 210 includes a light-emitting element 211 and a photosensitiveelement 212 coupled with the light-emitting element 211. In theembodiment, the light-emitting element 211 is a light-emitting diode,the photosensitive element 212 is a photosensitive diode. Eachlight-emitting element 211 includes a first terminal 211 a and a secondterminal 211 b, and each photosensitive element 212 includes a firstterminal 212 a and a second terminal 212 b. The first terminals 211 a ofthe light-emitting elements 211 in a single row are connected to a rowwire R_(i). The second terminals 211 b of the light-emitting elements211 in a single column are connected to a column wire L_(j). The firstterminals 212 a of the photosensitive elements 212 of one column areconnected together to form an output terminal O_(j). The second terminal212 b of each photosensitive element 212 is grounded, thus i=1, 2, . . .n, j=1, 2, . . . m.

Referring to FIG. 3, the photosensitive input device 1 further includesa controller 4, a storage device 5, a photoelectric detecting circuit 6,and a driving circuit 7.

The storage device 5 is connected to the controller 4, and storescoordinates in the system of the panel 2. The photosensitive units 210constitute the coordinates of the system of the panel 2, that is, thelight-emitting element 211 and the photosensitive element 212 of eachphotosensitive unit 210 represent particular coordinates of the systemof the panel 2.

The photoelectric detecting circuit 6 is connected to the photosensitiveelements 212 via the output terminal O_(i). The stylus 3 is operable byuser to emit light, when the light of the stylus 3 reaches one or morephotosensitive elements 212 of the induction layer 21, each of the oneor more photosensitive elements 212 senses the light to generate aninduced current I_(i). The output terminal O_(i) outputs the inducedcurrent I_(i) to the photoelectric detecting circuit 6. The inducedcurrent I_(i) precisely reflects the wavelength(s) of the light emittedby the stylus 3, where the induced current I_(i) includes the intensityvalue of the induced current I_(i) and the waveform of the inducedcurrent I_(i).

The photoelectric detecting circuit 6 is configured to determine whichone of the photosensitive elements 212 generates the induced currentI_(i), and therefore to determine the coordinates of the photosensitiveelement 212 that generates the induced current I_(i) and the coordinateof the light-emitting element coupled with the photosensitive element212, and is further configured to determine the intensity of the inducedcurrent I_(i).

The storage device 5 further stores a pre-defined table mapping arelationship between intensities of the inducted current I_(i) andbrightness levels of the light-emitting elements 211. The controller 4determines the desired brightness level according to the pre-determinedtable and the intensity of the induced current I_(i) as determined bythe photoelectric detecting circuit 6. The driving circuit 7 isconnected to the light-emitting elements 211 via the column wire L_(i),and configured to generate driving current in response to the desiredbrightness level determined by the controller 4, determine the columnwire L_(i) according to the coordinates of the photosensitive elements212 determined by the photoelectric detecting circuit 6, and furtherconfigured to output the driving current to the light-emitting elements211 which are coupled with the photosensitive elements 212 via thedetermined column wire L_(i) for adjusting the brightness of thelight-emitting elements 211. Thus, if the stylus 3 emits light with aspecific wavelength along a specific track across the panel 2, thelight-emitting elements 211 on the specific track are highlighted andthe brightness of the light-emitting elements 211 is adjusted inresponse to the user command, the specific track being visible on thepanel 2.

For example, if the stylus 3 emits light with a first wavelength whichstrikes the panel 2 along a specific track, the photosensitive elements212 illuminated thereby generate a first induced current. The controller4 determines the user command to be turn on the light-emitting elements211 or increase the brightness of the light-emitting elements 211,according to the pre-determined table and the intensity of the firstinduced current, and generates a corresponding first control signal. Thedriving circuit 7 turns on the light-emitting elements 211 or increasesthe brightness of the light-emitting elements 211 to correspond to thefirst control signal, which results in the specific track beingdisplayed. If the stylus 3 emits light with a second wavelength whichilluminates the panel 2 along the specific track, the photosensitiveelements 212 illuminated thereby generate a second induced current. Thecontroller 4 determines the command to be turn off the light-emittingelements 211 or decrease the brightness of the light-emitting elements,according to the pre-determined table and the intensity of the secondinduced current, and generates a corresponding second control signal.The driving circuit 7 thereby turns off the light-emitting elements 211or decreases the brightness of the light-emitting elements 211 tocorrespond to the command determined by the controller 4, which resultsin the specific track being unlit or having a decreased brightness.

It is understood that the present disclosure may be embodied in otherforms without departing from the spirit thereof. The present examplesand embodiments are to be considered in all respects as illustrative andnot restrictive, and the disclosure is not to be limited to the detailsgiven herein.

What is claimed is:
 1. A photosensitive input device, comprising: astylus operable to emit light beams; a photosensitive input panelcomprising: an induction layer comprising: a plurality of photosensitiveunits arranged in matrix, each of the plurality of photosensitive unitscomprising: a light-emitting element comprising a first terminal and asecond terminal, the first terminals of the light-emitting elementsarranged at a same row connected to a row wire, the second terminals ofthe light-emitting elements arranged at a same column connected to acolumn wire, and the light-emitting element representing a particularcoordinate of a coordinate system of the panel; and a photosensitiveelement coupled with the light-emitting element and corresponding to theparticular coordinate, the photosensitive element comprising a firstterminal and a second terminal, the first terminals of thephotosensitive elements arranged at a same column connected together toform an output terminal, the second terminal of each photosensitiveelement grounded, the photosensitive element configured to generate aninduced current when senses the light beams from the stylus, the outputterminal configured to output the induced current; a storage deviceconfigured to store a pre-defined table recording mapping relationshipbetween intensities of the induced current and commands of controllingthe light-emitting elements; a photoelectric detecting circuit connectedto the output terminals of the photosensitive elements, and configuredto determine the coordinate of the photosensitive element that generatesthe induced current and the coordinate of the light-emitting elementcoupled with the photosensitive element, and further configured todetermine the intensity of the induced current; a controller configuredto determine the command according to the pre-determined table and theintensity of the induced current determined by the photoelectricdetecting circuit; and a driving circuit connected to the column wires,and configured to generate driving current in response to the commanddetermined by the controller, determine the column wire according to thecoordinates of the photosensitive elements determined by thephotoelectric detecting circuit, and further configured to output thedriving current generated to the light-emitting elements coupled withthe photosensitive elements determined via the determined column wirefor controlling the light-emitting elements.
 2. The photosensitive inputdevice as recited in claim 1, wherein controlling the light-emittingelements comprises adjusting the brightness of the light-emittingelements.
 3. The photosensitive input device as recited in claim 1,wherein the photosensitive input panel further comprises a substrate anda cover, and the induction layer is sandwiched between the substrate andthe cover.
 4. The photosensitive input device as recited in claim 1,wherein the induced current precisely reflects the wavelength of thelights emitted by the stylus.
 5. The photosensitive input device asrecited in claim 4, wherein the induced current comprises the intensityvalue of the induced current and the waveform of the induced current. 6.A photosensitive input panel comprising: a substrate; and an inductionlayer disposed on the substrate, the induction layer comprising aplurality of photosensitive units arranged in matrix, each of thephotosensitive units comprising a light-emitting element and aphotosensitive element coupled with the light-emitting element, thephotosensitive element being operable to generate an induced currentwhen sensing light beams from a stylus, each photosensitive elementconnected to an output terminal configured to output the inducedcurrent, and each light-emitting element connected to a column wirewhich is configured to input a driving current generated in response tothe induced current to control the light-emitting element.
 7. Thephotosensitive input panel as recited in claim 6, wherein controllingthe light-emitting elements comprises adjusting the brightness of thelight-emitting elements.
 8. The photosensitive input panel as recited inclaim 6, wherein each light-emitting element comprises a first terminaland a second terminal, the first terminals of the light-emittingelements arranged at a same row connected to a row wire, the secondterminals of the light-emitting elements arranged at a same columnconnected to the column wire; each photosensitive element coupled withthe light-emitting element and corresponding to the particularcoordinate, the photosensitive element comprises a first terminal and asecond terminal, the first terminals of the photosensitive elementsarranged at a same column connected together to form the outputterminal, and the second terminal of each photosensitive element isgrounded.
 9. The photosensitive input panel as recited in claim 6,further comprising a cover disposed on the induction layer.
 10. Thephotosensitive input panel as recited in claim 6, wherein the inducedcurrent precisely reflects the wavelength of the lights emitted by thestylus.
 11. The photosensitive input panel as recited in claim 10,wherein the induced current comprises the intensity value of the inducedcurrent and the waveform of the induced current.
 12. A photosensitiveinput panel comprising: a substrate; and an induction layer disposed onthe substrate, the induction layer comprising: a plurality ofphotosensitive units arranged in matrix, each of the plurality ofphotosensitive units comprising: a photosensitive element coupled withthe light-emitting element and corresponding to the particularcoordinate, the photosensitive element comprising a first terminal and asecond terminal, the first terminals arranged at a same column connectedtogether to form an output terminal, each second terminal beinggrounded, the photosensitive element configured to generate an inducedcurrent when sensing the light beams from the stylus, the outputterminal configured to output the induced current; and a light-emittingelement comprising a first terminal and a second terminal, the firstterminals arranged at a same row connected to a row wire, the secondterminals arranged at a same column connected to a column wire, thecolumn wire configured to input a driving current generated in responseto the induced current to adjust the brightness of the light-emittingelement.
 13. The photosensitive input panel as recited in claim 12,further comprising a cover disposed on the induction layer.
 14. Thephotosensitive input panel as recited in claim 12, wherein the inducedcurrent precisely reflects the wavelength of the lights emitted by thestylus.
 15. The photosensitive input panel as recited in claim 14,wherein the induced current comprises the intensity value of the inducedcurrent and the waveform of the induced current.